Ruiz A J, Chan B B, Meyerhoefer T A, Buck D R, Farley P C, Flanagan T L, Kron I L
Department of Surgery, University of Virginia Health Sciences Center, Charlottesville 22908.
J Vasc Surg. 1991 Apr;13(4):487-90.
The vascular endothelium is important in the modulation of vascular tone via production of endothelium-derived relaxing and contracting factors. The abdominal aortas of five groups of rabbits were subjected to varying lengths of ischemia (0, 1, 2, 3, or 4 hours), removed, sectioned into transverse rings, and placed in tissue baths containing Krebs' buffer at 37 degrees C and aerated with 95% O2/5% CO2. After equilibration the rings were tested for endothelium-dependent vasodilation with methacholine and nonendothelium-dependent vasodilation with nitroprusside. Endothelium-dependent relaxation as elicited by methacholine was impaired at 3 and 4 hours of ischemia but was not significantly different at 1 and 2 hours as compared to control, whereas endothelium-independent vasodilation remained normal throughout the different periods of ischemia. The addition of 1 x 10(-6) mol/L rabbit hemoglobin reduced the time needed to demonstrate significant impairment of endothelial function to 2 hours. Endothelium-independent vasodilation was not affected by hemoglobin. We conclude that hemoglobin exacerbates ischemia vascular dysfunction in the rabbit aorta.
血管内皮通过产生内皮衍生的舒张和收缩因子在调节血管张力方面起着重要作用。将五组兔子的腹主动脉进行不同时长的缺血处理（0、1、2、3或4小时），取出后切成横向环，置于含有37℃ Krebs缓冲液并通以95% O₂/5% CO₂的组织浴中。平衡后，用乙酰甲胆碱测试环的内皮依赖性血管舒张，用硝普钠测试非内皮依赖性血管舒张。乙酰甲胆碱引发的内皮依赖性舒张在缺血3小时和4小时时受损，但与对照组相比，在1小时和2小时时无显著差异，而非内皮依赖性血管舒张在不同缺血时期均保持正常。添加1×10⁻⁶ mol/L兔血红蛋白可将显示内皮功能显著受损所需的时间缩短至2小时。非内皮依赖性血管舒张不受血红蛋白影响。我们得出结论，血红蛋白会加剧兔主动脉的缺血性血管功能障碍。
